Gran Telescopio Canarias
Optical telescope on La Palma, Spain
From Wikipedia, the free encyclopedia
The Gran Telescopio Canarias (GranTeCan or GTC) is a 10.4 m (410 in) reflecting telescope located at the Roque de los Muchachos Observatory on the island of La Palma, in the Canary Islands, Spain. It is the world's largest single-aperture optical telescope.[1]
Gran Telescopio Canarias, 2008 | |
| Alternative names | GranTeCan |
|---|---|
| Location(s) | La Palma, Atlantic Ocean, international waters |
| Coordinates | 28°45′24″N 17°53′31″W |
| Altitude | 2,267 m (7,438 ft) |
| Diameter | 10.4 m (34 ft 1 in) |
| Collecting area | 78.54 m2 (845.4 sq ft) |
| Focal length | 169.9 m (557 ft 5 in) |
| Website | www |
_OSM_map.jpg)  Location of Gran Telescopio Canarias | |
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Construction of the telescope took seven years and cost €130 million.[2][3] Its installation was hampered by weather conditions and the logistical difficulties of transporting equipment to such a remote location.[4] First light was achieved in 2007 and scientific observations began in 2009.[citation needed]
The GTC Project is a partnership formed by several institutions from Spain and Mexico, the University of Florida, the National Autonomous University of Mexico,[5] and the Instituto de Astrofísica de Canarias (IAC). Planning for the construction of the telescope, which started in 1987, involved more than 1,000 people from 100 companies.[3] The division of telescope time reflects the structure of its financing: 90% Spain, 5% Mexico and 5% the University of Florida.
History
First light
The GTC began its preliminary observations on 13 July 2007, using 12 segments of its primary mirror, made of Zerodur glass-ceramic by the German company Schott AG. Later, the number of segments was increased to a total of 36 hexagonal segments fully controlled by an active optics control system, working together as a reflective unit.[4][6] Its first instrument was the Optical System for Imaging and low Resolution Integrated Spectroscopy (OSIRIS). Scientific observations began in May 2009.[7]
Inauguration ceremony
The Gran Telescopio Canarias formally opened its shutters on July 24, 2009, inaugurated by King Juan Carlos I of Spain.[8] More than 500 astronomers, government officials and journalists from Europe and the Americas attended the ceremony.
Instrumentation
GTC hosts a suite of advanced instruments, including:
- OSIRIS: Optical System for Imaging and low-Intermediate-Resolution Integrated Spectroscopy The IAC's OSIRIS (Optical System for Imaging and low Resolution Integrated Spectroscopy), is an imager and spectrograph covering wavelengths from 0.365 to 1.05 μm. It has a field of view (FOV) of 7 × 7 arcmin for direct imaging, and 8 arcmin × 5.2 arcmin for low resolution spectroscopy. For spectroscopy, it offers tunable filters.[9]
- EMIR: Espectrógrafo Multiobjeto Infra-Rojo (near-infrared multi-object spectrograph)
- MEGARA: Multi-Espectrógrafo en GTC de Alta Resolución para Astronomía is an optical integral-field and multi-object spectrograph covering the visible light and near infrared wavelength range between 0.365 and 1 μm with a spectral resolution in the range R=6000–20000. The MEGARA IFU (also called the Large Compact Bundle, or LCB) offers a contiguous field of view of 12.5 arcsec x 11.3 arcsec, while the multi-object spectroscopy mode allows 92 objects to be observed simultaneously in a field of view of 3.5 arcmin x 3.5 arcmin by means of an equal number of robotic positioners. Both the LCB and MOS modes make use of 100 μm-core optical fibers (1267 in total) that are attached to a set of microlens arrays (with 623 spaxels in the case of the LCB and 92 x 7 in the case of the MOS) with each microlens covering an hexagonal region of 0.62 arcsec in diameter.[10]
- HiPERCAM: High-speed optical camera
- CanariCam: is designed as a diffraction-limited imager. It is optimized as an imager, and although it offered a range of other observing modes, these did not compromise the imaging capability. CanariCam worked in the thermal infrared between approximately 7.5 and 25 μm. At the short-wavelength end, the cut-off was determined by the atmosphere—specifically atmospheric seeing. At the long wavelength end, the cut-off was determined by the detector; this loses sensitivity beyond around 24 μm, although the cut-off for individual detectors varied significantly. CanariCam was a very compact design. It was designed for a total weight of the cryostat and its on-telescope electronics to be under 400 kg.[citation needed] Most previous mid-infrared instruments have used liquid helium as a cryogen; one of the requirements of CanariCam was that it should require no expensive and difficult to handle cryogens.[citation needed]. CanariCam used a two-stage closed cycle cryocooler system to cool the cold optics and cryostat interior to approximately 28 K (−245 °C; −409 °F), and the detector itself to around 8 K (−265 °C; −445 °F), the temperature at which the detector worked most efficiently. CanariCam was decommissioned as of February 2021[update].[11]
See also
- Other observatory sites
- Lists and comparisons